Simple mechanism for temporarily replacing a method's implementation e.g. for mocking during tests

simple mocking

var mockMethod = function(obj, methName, fn) {
	var orig = obj[methName];
	var handle = [obj, methName, orig];
	obj[methName] = fn;
	return handle;
}, unMockMethod = function(handle) {
	handle[0][handle[1]] = handle[2];
};

// usage: 
var hdl = mockMethod(dojo, "xhrGet", function() { 
	console.log("yep dojo.xhrGet would have been called");
});

dojo.xhrGet({ }); // logs, doesn't get anything

// restore it
unMockMethod(hdl);